Lamp filament support means

ABSTRACT

A single ended quartz halogen lamp having a coiled coil filament supported and axially aligned by a U-hook arrangement formed in each lead-in wire. The U-hooks are pressed between the coils of the filament to bear against a solid metal spud provided in each end of the filament. The configuration of the hook is such that the coil of the filament can pass through without being damaged in the process.

United States Patent [wj Flynn 51 Dec. 18,1973

Primary ExaminerRoy Lake Assistant Examiner-Darwin R. Hostetter Attorney-Norman J. OMalley et al.

[57 ABSTRACT A single ended quartz halogen lamp having a coiled coil filament supported and axially aligned by a U- hook arrangement formed in each lead-in wire. The U-hooks are pressed between the coils of the filament to bear against a solid metal spud provided in each end of the filament. The configuration of the hook is such that the coil of the filament can pass through without being damaged in the process.

1 Claim, 4 Drawing Figures PATENTEU an: 18 I975 LAMP FILAMENT SUPPORT MEANS BACKGROUND OF THE INVENTION I. Field of The Invention This invention pertains to incandescent lamps and particularly tubular lamps, in which a quartz envelope contains a quantity of halogen which has a regenerative effect on the filament and improves lamp maintenance. More specifically it pertains to a lamp wherein the lead in wires have formed hooks that support the filament coaxially within the envelope.

2. Description of the Prior Art The prior art discloses various methods of supporting the filament in axial alignment with the envelope. One method commonly used is that each end of the coiled coil filament is stretched at a point that leaves several turns intact at the veryend. This allows the end of a lead-in support wire tolbe fitted into these turns. Thereafter a hot crimping process secures the filament to the leadin wire.

Another method usedis that the filament is provided with hooked end spuds. These hooked end spuds are inserted into coils formed on each lead-in support wire. Thereafter the hooked end spuds are also hot crimped to the coils. v

In both of the above methods, the coils of the filaments are stabilized before the subassembly mounting step. The stabilization makes the coils very brittle. Thus it can be understood that when the coiled coil filament ends are stretched and hot crimped to the lead-in wires they often crack or will eventually have poor mechanical or electrical connections.

In the second method, where the hooked spuds are attached to the formed coils of the lead-in wires, the same problem will be present.

Both of the above described methods of filament support are also very expensive as well as unreliable.

SUMMARY OF-THE INVENTION My invention discloses a quartz halogen lamp with an improved filament mount. The filament support lead-in wires extend within the lamp envelope, by way of conventional molybdenum foil sections in the seal area and pass through a glass support rod. One lead-in wire terminates within the exhaust tube tip off which is centrally located at one end of the lamp. The other lead-in wire is terminated at the lower end of the filament.

Each of the lead-in wires is provided with a U-hook I form, that is inserted between the turn of the coil of the filament where they are securely hot crimped to insert spuds provided in each end of the filament.

The above type of support provides means for holding the filament in axial alignment without undue pressure on the turns of the filament.

BRIEF DESCRIPTION OF THE DRAWINGS the coils of the filament.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1 of the drawings, the lamp includes an envelope 1 with a tip off 3 from a residual exhaust tube (not shown). A conventional press seal 5 is disposed on the bottom end of envelope 1. Substan tially centrally disposed within the envelope is a coiled filament 7, supported by a pair of lead-in wires 9 and 11. The lead-in wire 9 extends to the upper end of the envelope 1, and is provided with an offset 10 that is heldin the exhuast tip off 3. Lead-in wire 11 extends only to the lower end of the filament. The lower ends of lead-in wire 9 and llpass through a quartz support rod 17 and are connected to molybdenum foil sections 13 and 15, that are compressed in the press seal 5. A conventional screw base 21 is disposed about the press seal 5. One of the lead-in wires is electrically connected to the shell of the base and the other lead-in wire is directed to a contact 23 at the lower end of base 21.

To properly support and align the filament within the envelope, a third support wire 25 extends from the quartz rod 17 and is attached to the mid point of the filament.

In my filament support arrangement, I form the ends of the filament with horizontal straight legs 26 and provide the legs with solid metal spuds 28 tightly fitted into the inner diameter of the coil section of the legs of the filament.

In FIGS. 3 and 4, an enlarged detail of the upper U hook configurations 30 are shown. This U-hook segment 30 is formed in each of the lead-in wires 9 and 11, at a point where the straight legs of the filament will in tersect. As seen in FIGS. 3 and 4., the U-hook is positioned between the turns of the filament coil 26 and the inner top portion of the U-hook is bent to bear against the spud 28. The shape of the U-hook is such that it provides an enlarged area for the connecting turn of the coil to pass through. A simple hot crimping operation is made to the U-hook 30 at the point of contact with the spud providing a locking arrangement for the filament.

The lower U-hook of lead-in wire 11 is identical to that of lead-in wire 9.

What I claim is:

l. A quartz halogen lamp comprising: a tubular envelope having a press seal at one end and having a substantially centered exhaust tube tip off at the other end; a quartz support rod located within said envelope; a pair of lead-in wires extending from the press seal of said envelope and passing through said support rod, the other end of one of said wires terminating in the tip off of said envelope and the other end of the other of said wires terminating slightly beyond said support rod, said lead-in wires having U-hooks formed therein near the ends thereof; a support wire extending from said quartz support rod and connected to the filament midway its length; a coaxially coiled-coil filament having right angle straight legs at each end thereof; solid metal spuds fitted within said legs whereby said U-hooks of said lead-in wires can be inserted between the coils of said filament to bear against said solid metal spuds to support said filament. 

1. A quartz halogen lamp comprising: a tubular envelope having a press seal at one end and having a substantially centered exhaust tube tip off at the other end; a quartz support rod located within said envelope; a pair of lead-in wires extending from the press seal of said envelope and passing through said support rod, the other end of one of said wires terminating in the tip off of said envelope and the other end of the other of said wires terminating slightly beyond said support rod, said lead-in wires having U-hooks formed therein near the ends thereof; a support wire extending from said quartz support rod and connected to the filament midway its length; a coaxially coiled-coil filament having right angle straight legs at each end thereof; solid metal spuds fitted within said legs whereby said U-hooks of said leadin wires can be inserted between the coils of said filament to bear against said solid metal spuds to support said filament. 